18
MSP
Medium RiskTCP/UDP — Messaging
Port Overview
Port Number
18
Service Name
MSP
Transport Protocol
TCP/UDP
Category
Messaging
Security Risk
Medium
Port Range
Well-Known (0-1023)
What is Port 18?
Message Send Protocol. A simple protocol for sending short messages between users on different hosts. Rarely used today.
TCP/UDP
Messaging
Security Considerations
Port 18 (MSP) is classified as medium risk. While this service is commonly exposed, consider using encrypted alternatives where available.
Recommendation: Keep the service updated. Monitor logs for unusual activity.